Suspension
Filed Sep 23, 2026
The rear subframe on the car is rusting badly and the Mercedes certified mechanic states that the entire frame needs replacement. With braking, the car could fishtail and be in a serious crash. The two model years prior to mine have had similar problems and a recall has been established for those years. I am asking the NHTSA to work with Mercedes-Benz to establish a recall for the 2015 C class before someone is injured as a result of this defect.
- NHTSA ID
- 11766545
- Incident
- Sep 23, 2026
The vehicle’s rear subframe has become severely rusted and structurally compromised. This failure has caused the vehicle to pull sharply to the right when the brakes are applied. The rear subframe and affected components are still on the vehicle and are available for inspection upon request. This condition creates a serious safety risk because the vehicle can suddenly pull hard to one side during braking, making it extremely difficult to maintain control. At highway speeds or during emergency braking, this could cause the driver to lose control of the vehicle, leave the roadway, collide with another vehicle or object, or potentially result in a rollover. The failure is especially concerning because it directly affects the stability and braking behavior of the vehicle. The problem was inspected and confirmed by Mercedes-Benz of Durham. The dealer determined that the rear subframe was severely rusted and that this condition was responsible for the vehicle pulling strongly to the right during braking. The vehicle has therefore been inspected by an authorized Mercedes-Benz dealership. The condition has not, to my knowledge, been inspected by police or insurance representatives. There were no warning lights, dashboard messages, or noticeable symptoms indicating that the rear subframe was deteriorating before the problem became apparent. There was no advance warning that the subframe had become severely rusted. The issue only became evident when the vehicle began pulling sharply to the right under braking. Because there were no warning signs before the failure, I believe this condition presents a significant safety hazard. A driver may continue operating the vehicle without knowing that the rear subframe has deteriorated to the point that vehicle stability and braking control are affected.
- NHTSA ID
- 11766498
- Incident
- Sep 21, 2026
Body & structureSuspension
Filed Sep 18, 2026
I noticed some unstable braking at higher speeds. I took the vehicle to a mechanic and he discovered severe rust with perforation of the rear subframe "very near to where some of the suspension connects to it and is allowing a lot of extra movement, especially under braking." He told me that the vehicle was unsafe to drive on the highway or at speeds over 40 mph and should be repaired, preferably through Mercedes as soon as possible. I've reached out to Mercedes Benz USA. They told me that this has been a common problem and some vehicles have had the warranty extended because of it. My vehicle is not included in the warranty extention but they suggested that it may be eligible for a "goodwill" repair. I've reach out to my local Mercedes dealership to further investigate the problem and are awaiting a return call.
- NHTSA ID
- 11765376
- Incident
- Sep 18, 2026
Powertrain (other)Suspension
Filed Sep 15, 2026
The rear structural subframe on my vehicle has experienced severe, premature corrosion perforation (rotting from the inside out), resulting in a major compromise of the vehicle’s structural integrity. This subframe is a critical safety component that supports the entire rear suspension, differential, and braking components. The subframe has rusted to the point of developing holes and structural cracks under normal operating conditions. This severe deterioration creates an immediate safety hazard, as a total failure or snapping of the subframe while driving can cause a sudden loss of vehicle control, unpredictable suspension geometry changes, and a severe risk of a high-speed crash.Mercedes-Benz has previously acknowledged an identical, widespread manufacturing defect and issued an extended 20-year warranty (NHTSA ID NCU-2023020004) for older model lines (such as the W204 and W212). However, my specific vehicle is currently excluded from that extension, despite suffering from the exact same premature metallurgical failure and safety risk. The deterioration is identical to the covered models, where road debris and water get trapped inside the hollow subframe unit, causing it to oxidize and disintegrate undetected from the interior until structural failure occurs.This constitutes a severe safety hazard. Driving with a compromised rear subframe risks a catastrophic detachment of the rear axle, control arms, and braking lines while at highway speeds. A sudden failure will lead to immediate loss of steering control and an incredibly high probability of a severe motor vehicle accident, endangering lives. I am filing this complaint to urge the NHTSA to investigate Mercedes-Benz and mandate an extension of the existing warranty framework to cover newer model years that exhibit the exact same premature corrosion failure. Dealers are denying coverage based on arbitrary VIN cutoffs, forcing owners to drive unsafe vehicles or pay out of pocket for a known structural defect.
- NHTSA ID
- 11764483
- Incident
- Sep 13, 2026
Body & structure
Filed Jul 18, 2026
The sunroof panel being cracked on this car is a well known and documented issue. There have been several recalls for it just not on my specific model. Yet I’m just like them, stuck with a broken in half sunroof panel that let water seep in and ruin my sunroof twice now, and the only fix is to pay $4500. This is insanely high for the small panel I’m talking about.
- NHTSA ID
- 11751245
- Incident
- Mar 11, 2025
Sunroof Glass failure vin:55SWF4KB1FU039607 2015 Mercedes C300 2PM July 16 2026, Tampa highway near college park east coordinates28.06840 N.82.35292W TEMPERATURE 91F
- NHTSA ID
- 11750865
- Incident
- Jul 16, 2026
Suspension
Filed Apr 7, 2026
Rear subframe has rust and holes. Dealer is saying not covered under warranty and asking for $8000
- NHTSA ID
- 11729627
- Incident
- Apr 6, 2026
I am reporting a structural failure of the rear subframe due to corrosion on my 2015 Mercedes-Benz C300 4MATIC. The failure was diagnosed by an authorized Mercedes-Benz dealer, who confirmed that the rear subframe has corroded and broken, compromising the structural integrity of the vehicle. This is not cosmetic rust. The subframe is a load-bearing structural component, and its failure creates a serious safety risk, including potential loss of vehicle control. I have been advised that the vehicle may be unsafe to operate in its current condition. The vehicle has approximately 143,000 miles and has been registered and operated in Connecticut, a salt-use state. However, this level of corrosion leading to structural failure of a major suspension component is premature and not consistent with normal wear and tear, even in such environments. I contacted Mercedes-Benz USA and escalated the matter to an Executive Referral Manager. Mercedes-Benz acknowledged the seriousness of the issue but declined to provide any repair assistance, stating that my vehicle falls outside of warranty extension and goodwill parameters. Mercedes-Benz did not dispute the nature of the failure or its safety implications, but refused to address the issue based solely on internal policy criteria such as age and mileage. A rear subframe supports critical suspension components. Corrosion leading to structural breakage can result in instability, misalignment, or failure of suspension components while driving, increasing the risk of a crash. This issue appears to be consistent with known reports of rear subframe corrosion in similar Mercedes-Benz vehicles, raising concern about a broader safety defect. The failure was identified during inspection, and repair costs are estimated at approximately $5,000–$6,000. I am submitting this complaint due to the safety risk posed by structural failure and the manufacturer’s refusal to address the issue.
- NHTSA ID
- 11724925
- Incident
- Jan 19, 2026